ELCB CONNECTION

The ELCB will work correctly if you just connect the 3 phases through it, and leave 1 pole spare.

If you want the test button to work, usually the pole left unconnected should be one of the outside poles, 1 or 4, as the test button works between poles 2 and 3.

It was a new knowledge for me that the ELCB works in 3 phase with no neutral.!!!Will it work actually ?Have u ever seen this......?

Seen, it, done it many times, mainly when protecting reefers (refrigerated shipping containers) which all have 3-phase motors (no neutral) and must be RCD-protected in container parks here (NZ).

A basic grasp of 3-phase theory will greatly assist you in understanding how this works.

I have a thourough idea of the working of ELCb,where it continously samples the phase n neutral sum of which will be zero always......Ia+Ib+Ic+In=0...in 3 phase systems Ia
+Ib+Ic=0...but I haven't seen a 4p Elcb working on a 3 phase systems........

As yours is a 3-phase balanced kind of load, here there will not be any neutral current. All the three phases will be loaded equally. Still your equation will hold good.

Ia + Ib + Ic + In = 0

(i.e.) Ia + Ib + Ic + 0 = 0 in your case.

Any earth fault inside the machine, this balance is affected and the ELCB operates.

I agree with Paul, but ensure the working of the TEST facility after connecting as above.

Its never possible as Ia+Ib+Ic =0 in 3 wire system and if u connect 4p ELCB in that system the total current of that is always zero.So no net induction to the coil on earth fault is also zero.........

RYB+N should be coonected to ELCB AND EARTH IS CONNECTED ALSO BUT DIRECT TO EARTH BAR